【摘要】 通过修正的Landau-Devonshire热力学模型构建了PbZr_0.4Ti_0.6O₃/SrTiO₃异质结的电滞回线方程,得到了剩余极化强度P_r、矫顽电场E_c和有效储能密度W_rec的关于PbZr_0.4Ti_0.6O₃薄膜厚度h的解析函数,进而研究了连续厚度h对PbZr_0.4Ti_0.6O₃薄膜铁电性能和铁电储能性能的影响。结果表明,P_r,E_c和W_rec均随PbZr_0.4Ti_0.6O₃薄膜厚度h的增加呈非线性增大,且当厚度h分别为57.0 nm、64.2 nm和65.8 nm时,达到饱和值75.3μC·cm^-2、2 240.7 kV·cm^-1和9.0 J·cm^-3,而能量转换效率η随h的增加呈现出非线性减小,h接近52.6 nm时,η趋于一稳定值4.79%。此外,瞬时相对变化率■和■均随h增加而减小,当h小于2.4 nm时,■大于■,当h大于2.4 nm时,■小于■,且当h接近50.0 nm时,■趋于一稳定值0.65。更多还原

【Abstract】 The hysteresis loop equation of PbZr_0.4Ti_0.6O₃/SrTiO₃ hetero-junction was constructed by the modified Landau-Devonshire thermody-namic model, and the analytical functions of remanent polarization intensity P_r, coercive electric field E_c and effective energy storage density W_recwith respect to the thin film thickness h of PbZr_0.4Ti_0.6O₃ were obtained, respectively, and then the effects of the thickness of the PbZr_0.4Ti_0.6O₃ thin films on ferroelectric properties and ferroelectric energy storage properties were investigated. The results show that P_r, E_c and W_rec all increase nonlinearly with the increase of PbZr_0.4Ti_0.6O₃ film thickness h, and reach saturation values of 75.3 μC·cm^-2, 2 240.7 kV·cm^-1 and 9.0 J·cm^-3 when the thickness h is 57.0 nm, 64.2 nm and 65.8 nm, respectively, the energy storage conversion efficiency η, however, decreases nonlinearly with the increase of h, reaching a stable value of 4.79% when h is close to 52.6 nm. In addition, both ■ and ■, the instantaneous relative rates of change, decrease with the increase of h, when h is less than 2.4 nm, ■ is greater than ■, when h is greater than 2.4 nm, ■ is less than ■, and ■ tends to a stable value of 0.65 as h is close to 50.0 nm.更多还原